1. Field of the Invention
The present invention relates to a fuel tank opening-closing device for supplying fuel to a fuel tank, which opens a flap valve using the insertion force of a fueling nozzle.
2. Description of the Related Art
Fuel tank opening-closing devices are disclosed in JPA2010-195344 and JPA2010-522118. The fuel tank opening-closing devices are equipped with a shutter mechanism for opening and closing an insertion path of a tank opening forming member, and an opening-closing activation mechanism which permits the opening operation of the shutter mechanism. The opening-closing activation mechanism is equipped with a nozzle detection mechanism and a locking mechanism. The locking mechanism has lock engaging members which are disposed at both sides of the insertion path and engage or release parts of the outer circumference of the flap valve. When the fueling nozzle is inserted during fueling, by the end of the fueling nozzle touching the nozzle detection member, the lock engaging member is moved outward in the radial direction, and then being moved from the locked position to the unlocked position, permits the opening operation of the shutter mechanism. Then the shutter is opened by pressing with the end of the fueling nozzle, and fueling is performed.
However, in the related fuel tank opening-closing device (JPA2010-195344), when the insertion path diameter has been made larger to deal with variation in the outer diameters of fueling nozzles, there was the problem that the nozzle detection member touches only one of the lock engaging parts and releases the locked position, not touched other of the lock engaging parts. Therefore, it was difficult for the other of locking member to be released from the locked position.
A pressure regulating valve is stored in the opening-closing member shown in JPA2010-522118. The pressure regulating valve adjusts pressure to within a preset pressure range in the insertion path and fuel passage in a state when the opening-closing member closes the inlet. The opening-closing member had the problem that when the pushing force by the end of the fueling nozzle is great, and reaches the point of damaging the opening-closing member, it is easy to have damage on the function of the pressure regulating valve. Because of that, the mechanical strength of the opening-closing member has to be set high.